Takashi was just Ezaki‘s surname. Don’t know how the other guy with the glasses was called, but it’s probably him. Which is sad because he seemed like the only guy in the entire series who would actually be able to survive an apocalypse.
Maybe death matches is how they merge… But I think this all happens at the same time as when the trans girl (Oda’s Sister) turned. That’s when Kurusu had that conversation with himself, but actually Hideo.